Question

An athlete completes one round of a circular track of diameter 100 m in 15 sec. What will be the distance and displacement after 3 min 30 seconds

Answer 1

Dear Student

​​​​​​

Diameter of a circular track, d = 100 m

Radius of the track, r = d/2 = 50 m

Circumference = 2πr = 2π (50) = 100π m

In 15 s, the given athlete covers a distance of 100π m.

In 1 s, the given athlete covers a distance = 100π/15 m

The athlete runs for 3 minutes 30 s = 210 s

∴Total distance covered in 210 s = (100π/15) × 210 = 4400 m

Displacement after 3 m 30 sec in 210 s.
Rotating in 15 s = 1
Rotating in 1 s = 210
Rotating in 210 s = 1/15 × 210 = 14

So, displacement is zero.

Regards